When using automatically filling replenishing shuttles such as shown in U.S. Pat. Nos. 1,574,643 and 1,812,087, on weaving looms, it is necessary to continuously replenish the shuttle automatically with a refilled bobbin. In so doing, the empty or used bobbin is pushed or ejected out of the shuttle by the insertion of the refilled bobbin. However, in ordinary practice, the ejected bobbin is not completely empty and may have from 7 to 13 yards of unused yarn left thereon. Therefore, the ejected bobbin must be completely unwound or stripped of yarn before it can be refilled with yarn. The ejected bobbin is usually delivered to an automatic yarn filling machine having a yarn stripper such as the Unifil Loom Winder, Model No. 790, made by the Leesona Corp., wherein a transfer tail of the unused yarn trailing from the ejected bobbin is caught by the stripper and the unused yarn is wound around a comb in the stripping machine. The empty bobbin is then filled or rewound with new yarn.
In many instances, however, an adequate transfer tail of yarn is not created when the used bobbin is ejected from the shuttle. As the used bobbin is ejected from the shuttle, it is caused to rotate in one direction or the other. Generally, if the bobbin rotates in a direction opposite to that in which the unused yarn is wound, the creation of an adequate transfer tail tends to be impaired, however, if the bobbin is caused to rotate in the same direction in which the unused yarn is wound, the creation and separation of an adequate transfer tail will be enhanced.
If an adequate transfer tail is not created on the ejected bobbin, the bobbin will not be unwound or stripped by the stripping machine and will have to be stripped manually by the machine attendant. Quite often an unstripped bobbin will not be ejected by the stripping machine and will be delivered back to the automatic filling machine with new yarn being wound upon the unused yarn. When this is done, a defect can occur in the fabric being woven and can cause other operational damage during the weaving process. Therefore, it is expedient to maximize the likelihood that an adequate transfer tail of unused yarn will be created on the used bobbin when ejected from the shuttle which is afforded when using a shuttle spring constructed in accordance with the present invention.